In co-pending application Ser. No. 06/565,540, filed Dec. 27, 1983, and assigned to the assignee herein, a viscous product dispenser is disclosed showing an actuating lever provided with an intergral, external valve that opens and closes the discharge outlet of the spout. That arrangement has proved to be very attractive in many respects, particularly where the function of a checking outlet valve is desired that will not interfere with or disrupt the laminar flow of product from the dispenser during the pumping stroke, e.g., where the product being dispensed comprises toothpaste having layers of striping substance carefully laminated therein and whose integrity must be maintained for aesthetic reasons in the bead of product which is dispensed from the unit.
It has been found, however, that the "trapdoor-like" movement of the prior valve during closing tends to cause a quantity of the product to be pressed against the spout and create an unsightly residue. This also tends to cause the dispensed product bead to adhere to the valve and not fully separate from the product remaining within the spout. Additionally, it has been found that in some cases product is attempted to be pumped out of the spout by the moving pumping piston before such time as the valve flap has adequately uncovered the outlet.